scholarly journals Investigation of Viscoelastic-Creep and Mechanical-Hysteresis Behaviors of Hydrostatically Stressed Crystal Using the Phase Field Crystal Method

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
J. Em-Udom ◽  
N. Pisutha-Arnond
Keyword(s):  
Phase Field ◽  
Density Functional ◽  
Applied Pressure ◽  
Pressure Oscillation ◽  
Complex Moduli ◽  
Viscoelastic Creep ◽  
Mechanical Hysteresis ◽  
Deformation Problem ◽  
The Impact ◽  
Phase Field Crystal

The phase field crystal (PFC) method is a density-functional-type model with atomistic resolution and operating on diffusive time scales which has been proven to be an efficient tool for predicting numerous material phenomena. In this work, we first propose a method to predict viscoelastic-creep and mechanical-hysteresis behaviors in a body-centered-cubic (BCC) solid using a PFC method that is incorporated with a pressure-controlled dynamic equation which enables convenient control of deformation by specifying external pressure. To achieve our objective, we use constant pressure for the viscoelastic-creep study and sinusoidal pressure oscillation for the mechanical-hysteresis study. The parametric studies show that the relaxation time in the viscoelastic-creep phenomena is proportional to temperature. Also, mechanical-hysteresis behavior and the complex moduli predicted by the model are consistent with those of the standard linear solid model in a low-frequency pressure oscillation. Moreover, the impact of temperature on complex moduli is also investigated within the solid-stabilizing range. These results qualitatively agree with experimental and theoretical observations reported in the previous literature. We believe that our work should contribute to extending the capability of the PFC method to investigate the deformation problem when the externally applied pressure is required.

scholarly journals Heterogeneous nucleation of/on nanoparticles: a density functional study using the phase-field crystal model

2014 ◽  
Vol 43 (7) ◽  
pp. 2159 ◽  
Author(s):  
László Gránásy ◽  
Frigyes Podmaniczky ◽  
Gyula I. Tóth ◽  
György Tegze ◽  
Tamás Pusztai
Keyword(s):  
Phase Field ◽  
Heterogeneous Nucleation ◽  
Density Functional ◽  
Functional Study ◽  
Density Functional Study ◽  
Crystal Model ◽  
Phase Field Crystal

Atomic density functional and diagram of structures in the phase field crystal model

2016 ◽  
Vol 122 (2) ◽  
pp. 298-309 ◽  
Author(s):  
V. E. Ankudinov ◽  
P. K. Galenko ◽  
N. V. Kropotin ◽  
M. D. Krivilyov
Keyword(s):  
Phase Field ◽  
Density Functional ◽  
Atomic Density ◽  
Crystal Model ◽  
Phase Field Crystal

Numerical study of the liquid-solid interface properties for binary alloys using phase-field crystal approach

2013 ◽  
Vol 1535 ◽  
Author(s):  
Muhammad Ajmal Choudhary ◽  
Julia Kundin ◽  
Heike Emmerich
Keyword(s):  
Phase Field ◽  
Solid Phase ◽  
Numerical Study ◽  
Liquid Droplet ◽  
Alloy System ◽  
Model Parameters ◽  
Systematic Analysis ◽  
Solid Interface ◽  
The Impact ◽  
Phase Field Crystal

ABSTRACTThe phase-field crystal (PFC) method has emerged as a promising technique to simulate the evolution of crystalline patterns with atomistic resolution on mesoscopic time scales. We use a 2D PFC model based on Elder et al. [Phy. Rev. B 75, 064107 (2007)] to perform a systematic analysis of a liquid-solid interface for a binary alloy system. We propose the method of determining interfacial energies for a curved liquid-solid interface by stabilizing the circular solid seed in the surrounding liquid phase and the liquid droplet in the solid phase for various seed sizes in a finite system. We also investigate the impact of model parameters on the resulting interface energies. The interface energies are computed with various system sizes in order to study the system size effects. In particular, we compare the simulation results in the form of the interface energy as a function of radius with the existing theories.

Theoretical Calculations of Mechanical, Electronic, and Chemical Bonding in CaN2, SrN2, and BaN2

2014 ◽  
Vol 69 (12) ◽  
pp. 619-628 ◽  
Author(s):  
Li-Qin Zhang ◽  
Yan Cheng ◽  
Zhen-Wei Niu ◽  
Chang-Ge Piao ◽  
Guang-Fu Ji
Keyword(s):  
Bulk Modulus ◽  
Bond Length ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Applied Pressure ◽  
Theoretical Data ◽  
High Hardness ◽  
Mechanical Instability ◽  
Spin Polarized ◽  
The Impact

AbstractWe present a first-principles density functional theory-based study about the impact of pressure on the structural and elastic properties of bulk CaN2, SrN2, and BaN2. Non-spin and spin polarized calculations indicate that the non-spin polarized ground state was more favourable with magnetic moments of 1.049 μB, 1.059 μB, and 1.014 μB for CaN2, SrN2, and BaN2, respectively, and these were in good agreement with previous experimental and theoretical data. The high bulk modulus of CaN2, SrN2, and BaN2 confirm that those compounds have low compressibility and high hardness. The obtained bulk modulus, N-N bond length, and optimized structure parameters are similar to those from previous studies.With an increase in applied pressure the independent elastic constants of CaN2, SrN2, and BaN2 indicated the presence of mechanical instability at 20, 15, and 10 GPa, which is possibly related to phase transitions in addition to a decrease in N-N bond length.

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